1. Technical Field
The present disclosure relates to a quantum interference device, an atomic oscillator, an electronic apparatus, and a vehicle.
2. Related Art
Hitherto, an oscillator which oscillates based on energy transition of atoms of alkali metal, such as rubidium or cesium is known. For example, see Proceedings of the 39th Annual Precise Time and Time Interval Meeting (2007)/The Chip-Scale Atomic Clock—Prototype Evaluation (“Chip-Scale Atomic Clock Prototype Evaluation”, hereinafter).
An oscillator described in the Chip-Scale Atomic Clock Prototype Evaluation has a cell which is filled with gaseous alkali metal, a vertical cavity surface emitting laser (VCSEL) which emits light for exciting cesium in the cell, a photodiode which detects light transmitted through the cell, and a spacer which is provided between the VCSEL and the cell. In the oscillator, the VCSEL, the spacer, the cell, and the photodiode are arranged in a line in this order.
In order to increase oscillation characteristics of the oscillator, it is necessary to increase the diameter (i.e., width) of light incident in the cell.
However, for the oscillator described in the Chip-Scale Atomic Clock Prototype Evaluation, since light is incident in the cell in a state of the radiation angle of the VCSEL, and to increase the diameter of light that is incident on the cell, the distance between the VCSEL and the cell should be increased. For this reason, there is a problem in that the oscillator cannot be reduced in size.